Area of use
Molding plaster is intended for casting molds in the ceramic industry by the technology of multiple casting, including Spagless. A special feature of this technology is the drying of plaster molds with cavities inside with compressed air at low pressure, what can significantly increase performance by increasing the number of cycles of operation forms per day.
It is also possible to use it for casting of sculptural models, plaster stucco ornaments.
Manufacturing base
For the production of molding plaster gypsum binders are used with premium а and β - modifications with use of mineral and chemical additives that increase the absorption and turnover of plaster molds.
Plaster is easily soluble, homogenously set in the mold, finely dispersed, what provides high smoothness of the surface of the finished products. Color is from white to light pink.
Specification
To confirm the technical characteristics the standard test methods are used in accordance with the requirements of normative documents of Samara Gypsum Plant CJSC GOST 125-79 and TU 21-RSFSR-153-90.
| Gypsum/water ratio | 1,35 - 1,5 |
| Setting time, min. |
| - starting | 10 - 20 |
| - end | 15 - 25 |
| Rest on the sieve Ф =0,2 mm, % | Max. 1 |
| Cubic expansion , % | 0,10 - 0,15 |
| Metallic contaminants content, mg/kg | Max. 1 |
| Strength of test beams in 2 hours, kgf/cm2 |
| - under bending | Min. 35 |
| - under compression | Min. 70 |
| Absorption of water, % | 35 - 40 |
Water-solid ratio is not a mandatory value and can be selected individually by each user depending on the application area.
Depending on its value other product characteristics such as strength, setting time and water absorption (porosity), can also vary.
Packing and marking
Molding plaster is packed in 3-ply bags of micro-crepe paper with a single layer of cellophane inside on wooden pallets. Another type of package will be considered in accordance with the need of the client.
Storage conditions
Plaster mix should be stored in a dry room, avoiding direct impact of excess moisture, as excessive moisture leads to the changes in the properties and technical characteristics of the product (reduction in strength and increase in setting time).
The material should be used immediately after the package opening.
